Correction to This Article
In some July 17 editions, a map with an article about suicide bombings misstated the year of the first suicide terrorist attack in the United States as 2003. The first such attacks were those of Sept. 11, 2001.

Unheard of only a few decades ago, suicide bombings have rapidly evolved into perhaps the most common method of terrorism in the world, moving west from the civil war in Sri Lanka in the 1980s to the Palestinian intifada of recent years to Iraq today. Since the Sept. 11, 2001, suicide attacks in the United States, suicide bombers have struck from Indonesia to India, from Russia to Morocco.

Now governments throughout the West -- including the United States -- are bracing to cope with similar challenges in the wake of the deadly July 7 subway bombings in London, which marked the first time that suicide bombers had successfully mounted an attack in Western Europe.

The pace of such attacks is quickening. According to data compiled by the Rand Corp., about three-quarters of all suicide bombings have occurred since the Sept. 11 attacks.

The numbers in Iraq alone are breathtaking: About 400 suicide bombings have shaken Iraq since the U.S. invasion in 2003, and suicide now plays a role in two out of every three insurgent bombings. In May, an estimated 90 suicide bombings were carried out in the war-torn country -- nearly as many as the Israeli government has documented in the conflict with Palestinians since 1993.

Yesterday, a suicide bomber detonated explosives strapped to his body inside a Shiite mosque south of Baghdad, triggering a huge fuel-tanker explosion that killed at least 54 people, according to police.

The bombings in London, which killed 55 people, illustrate the profound difficulty of preventing such attacks, experts say. Intelligence officials believe the bombers, in a common pattern, were foot soldiers recruited for the occasion, young men of Pakistani and Jamaican backgrounds reared in Britain who had recently converted to radical Islam. The four bombings required no exit strategy and were pulled off with devices that apparently were made in a bathtub and were small enough to fit in backpacks.

"With the exception of weapons of mass destruction, there is no other type of attack that is more effective than suicide terrorism," said Bruce Hoffman, a terrorism expert who heads the Washington office of Rand, a California think tank. "The perception is that it's impossible to guard against."

The motives behind suicide bombings are often mixed. Terrorism experts and intelligence officials disagree on the extent to which political strategy and religious fervor have led to the rising frequency of such attacks. But in addition to the death toll, a key objective of such bombings is clearly to sow terror by violating deeply held cultural and religious taboos against suicide, experts say.

Daniel Benjamin, a senior fellow at the Center for Strategic and International Studies and a former Clinton administration counterterrorism official, points to the frequent glorification of death and martyrdom by the leaders of al Qaeda and other extremist groups. In his famous fatwa , or declaration of war, against the United States in 1996, al Qaeda leader Osama bin Laden told U.S. officials: "These youth love death as you love life."

"This is their way of saying they are much more determined than we are," said Benjamin, who co-wrote the 2002 book "The Age of Sacred Terror."

"They realize we are very unnerved by this. . . . I see the spread of it as a tactic as an indication of the strength of the ideology for Muslim radicals," Benjamin said.

History of Suicide Attacks

The use of suicide attacks is not new. Japanese kamikaze pilots in World War II tried to cause maximum damage by crashing their fighter planes into U.S. ships. Walter Laqueur, an expert in the history of terrorism, also says that, for centuries, any attack on military or political leaders was a form of suicide because the act usually occurred at close quarters and brought swift and certain death for the killer.

One watershed came in 1983, when a Hezbollah operative drove his truck into the U.S. Marine barracks in Beirut, killing 241 U.S. service members in an attack that remains the deadliest terrorist strike on Americans overseas. Hezbollah would later carry out several dozen more suicide attacks.

Most experts agree that the modern style of suicide bombings first gained its greatest prominence outside the Middle East, in the island nation of Sri Lanka.

The Liberation Tigers of Tamil Eelam, popularly known as the Tamil Tigers, is an avowedly secular rebel movement of the country's Tamil ethnic minority. It carried out scores of suicide bombings from the late 1980s until a cease-fire in 2002. The conflict between the Tigers and the government, which is dominated by members of the Sinhalese majority, began in 1983 and claimed an estimated 65,000 lives.

Though dominated by Hindus, the Tigers are predominantly ethnic and nationalist in outlook, with religion not playing a significant role in their actions. The Tigers' early and aggressive use of suicide attacks, analysts say, reflected a pragmatic calculation of the need to level the military playing field against a larger and better-equipped foe.

The group created an elite force to carry out such attacks, the Black Tigers, whose members underwent rigorous training and were reportedly treated to dinner with rebel leader Velupillai Prabhakaran before being sent on their missions.

The rebels carried out their first suicide bombing in 1987, when a captain blew himself up along with 40 government troops at an army camp in the northern part of the country. Tamil Tiger spokesmen emphasize the use of suicide attackers against military targets, but the group has also used them against political and economic targets in strikes that have cost hundreds of civilian lives.

In 1991, a suspected Tamil Tiger assassinated former Indian prime minister Rajiv Gandhi. Two years later, a suicide bomber killed Sri Lankan President Ranasinghe Premadasa and 23 others in Colombo. Tamil Tiger suicide attackers also staged devastating strikes on the country's central bank, its holiest Buddhist shrine and its international airport.

Robert A. Pape, an associate professor of political science at the University of Chicago, calls the group the world's "leading instigator" of suicide attacks. In his recent book "Dying to Win: The Strategic Logic of Suicide Terrorism," Pape says that the group accounted for 76 of 315 suicide attacks carried out around the world from 1980 through 2003, compared with 54 for the Islamic Resistance Movement, or Hamas, and 27 for Islamic Jihad.

Some analysts say the group's strategy, though reprehensible, was effective in pushing the government toward a negotiated settlement.

"The suicide bombings in civilian areas, especially outside the conflict zones of the northeast, brought to the people outside the horror of the war and the vulnerability of society, " Jehan Perera of the National Peace Council, an advocacy group in Colombo, said in a telephone interview.

Laqueur, the author of "A History of Terrorism" and other books, disagrees, noting that the Tigers' primary goal -- to gain power -- has not been achieved after more than two decades of bloodshed. But he said Sri Lanka does illustrate how religious extremism has not always been central to the tactic. "It's not purely a religious thing; it's fanaticism," Laqueur said in an interview from London. "It just happens that, now, we are seeing the fanaticism primarily with Islam."

Iraq Is Now the Focus

Even as the Tigers have abandoned suicide attacks, others have adopted the tactic as their own. In Russia, Chechen Muslim radicals have mounted at least 19 suicide operations, according to Pape's statistics, including those in one terribly deadly week last year when hundreds died in a fiery siege at a school, a bombing at a Moscow train station and the downing of two airliners.

Al Qaeda has also favored suicide plots on more than 20 occasions since 1996 against the United States and its allies, including the unprecedented Sept. 11, 2001, hijackings that killed nearly 3,000 people.

But for sheer volume, Iraq is now the global center of suicide terrorism. In the days before yesterday's bombing, 27 people, mostly children, died in a suicide attack staged as soldiers handed out treats, and at least 25 others were killed when 10 suicide bombers targeted vehicles in coordinated attacks in Baghdad.

Though sporadic ambushes and roadside bombings began to plague U.S.-led occupation troops almost immediately after the fall of Saddam Hussein's dictatorship in April 2003, the beginning of a full-fledged insurgency is generally traced to the suicide car bombing of the Jordanian Embassy in Baghdad on Aug. 7 of that year. The attack, which killed 14, was followed two weeks later by a suicide truck-bomb attack that destroyed the U.N. headquarters in Baghdad and killed at least 20 people.

"If we look at what it takes to drive a bomb-laden vehicle into a crowd of people, it is not that challenging to perform that function -- especially if you're willing to give your life," Alston said.

Who the suicide bombers are, and what motivates them, remains much less clear in Iraq than in Israel and the occupied territories, where the attackers' identities are quickly and widely disseminated by Palestinian factions and Israeli authorities.

Neither side in the Iraqi conflict has been willing or able to release detailed information on suicide bombers. U.S. and Iraqi authorities say they are certain that the vast majority of suicide bombers come from outside Iraq. But gathering forensic evidence is often impossible because of the continuing danger at bombing sites.

Pape says that attacks in Iraq and elsewhere show that "the connection between Islamic fundamentalism and suicide bombing is misleading."

"The logic driving these attacks is mainly a strategic goal: to compel the U.S. and other countries to remove their forces from the Arabian peninsula," Pape said. "The London attacks are simply the next step in al Qaeda executing its strategic logic."

Others disagree, arguing that even if terrorist leaders have strategic reasons for choosing suicide attacks, the bombers and their families are often motivated by religious belief. Hoffman calculates that 31 of 35 groups that have used suicide bombings are Islamic.

"To try to reduce it to an agenda that is purely political is to misunderstand religion," Benjamin said. "The reason that bin Laden and his followers want the U.S. out of the Middle East has religious roots."

The Cult of Glorification

The boys all know the way to Ahmed Abu Khalil's house, tucked along an alley in a neighborhood of the West Bank town of Atil known as Two Martyrs. Abu Khalil, 18, became its third after he blew himself up Tuesday near a shopping mall in the Israeli city of Netanya.

It is safe to say Abu Khalil knew how he would be remembered here for his twilight attack outside the HaSharon Mall, which killed five Israelis, including two 16-year-old girls who were lifelong best friends. Scores more were injured in Israel's third suicide bombing this year.

The neighborhood is named for two local members of Islamic Jihad, the radical Palestinian group, who died fighting in the West Bank city of Jenin in 2003. The stylized posters of young men, posing with assault rifles and draped with ammunition belts, wallpaper the city. Graffiti urges uprising.

"This has given us a lot of pride, what he has done in Netanya," said Ibrahim Shoukri, 14, who used to follow Abu Khalil to prayer at the mosque. "We hope all of us will be like him."

The cult of glorification -- a mix of nationalist, personal and religious fervor -- that surrounds suicide bombers has long been one of the most difficult challenges facing Israeli security officials. Religious justification taught in the more radical West Bank mosques and intense familial pride -- at least in the days immediately after the attacks -- often outweigh the Israeli deterrent measures designed to make would-be suicide bombers think twice.

Judging by statistics, Israeli officials have made significant progress against suicide attacks since the start of the intifada in September 2000. At the height of the uprising in 2002, 42 suicide bombings killed 228 people. Two years later, the number had dropped to 12 bombings and 55 deaths.

Israeli officials say the construction of a concrete barrier that rises 24 feet high in some places and the intensive military operations in the West Bank have helped keep suicide bombers out of Israel. In addition, the Israeli military destroys the family homes of suicide bombers, a practice human rights groups have condemned as an illegal exercise of collective punishment.

Dore Gold, an adviser to Prime Minister Ariel Sharon, said the tactic is designed in part to counter the financial incentives offered by enemy governments -- and some nongovernmental groups in Arab countries -- which encourage the bombings. Hussein's Baath Party, for example, sent $15,000 checks to bombers' families, a lot of money in poor West Bank towns.

"If you know your family will be impoverished as a result of your act, then that may affect the calculus," Gold said.

In Atil on Tuesday morning, Abu Khalil left his house at 7 a.m., telling his family he was on his way to check his test scores. He never returned. The family found out about his attack from the television news.

Within hours, Israeli soldiers arrived at the family home. They arrested Khalil's father, who is now in an Israeli military prison outside the northern West Bank. Why and how Abu Khalil carried out the bombing remains a mystery. "God knows how he got through the wall," said an uncle, Burhan Abu Khalil. "The Islamic Jihad organizes those things."

One recent morning, Palestinian television crews filled the family courtyard. As more than a dozen teenage boys looked on, the reporters posed 14-year-old Mahmoud and 4-year-old Othman with their brother's picture, seeking their impressions. They put a black Islamic Jihad cap on Mahmoud's head.

"Put the picture here on your chest," the leader of a crew instructed Othman, the videotape rolling. "What did he tell you, what did he tell you?"